GNU bug report logs - #17806
24.4.50; Branch emacs-24 fails to beuild on Debian

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Message #43 received at 17806 <at> debbugs.gnu.org (full text, mbox):

From: Paul Eggert <eggert <at> cs.ucla.edu>
To: Glenn Morris <rgm <at> gnu.org>, 17806 <at> debbugs.gnu.org
Cc: Manoj Srivastava <srivasta <at> golden-gryphon.com>,
 Dmitry Antipov <dmantipov <at> yandex.ru>
Subject: Re: bug#17806: 24.4.50; Branch emacs-24 fails to beuild on Debian
Date: Fri, 20 Jun 2014 12:48:02 -0700

[Message part 1 (text/plain, inline)]

Glenn Morris wrote:
> Why does Emacs even have --enable-link-time-optimization as a configure
> option? Does it provide any measurable benefit?

It's supposed to have better runtime performance.  In my standard little 
benchmark, though, --enable-link-time-optimization slowed down runtime 
CPU performance by 14% (x86-64, GCC 4.9.0).  It did shrink the 
executable's text size by 2.4%, but I'd rather have the CPU performance.

I installed the attached as emacs-24 bzr 117269 to try to discourage 
casual use.  Another possibility would be to remove 
--enable-link-time-optimization, but I suppose that should be done in 
the trunk if it's done at all.  I'll CC: this to Dmitry as he added the 
option in the first place.

[lto-diag.patch (text/plain, attachment)]

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